<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>动态霓虹灯边框效果</title>
    <style>
        html,body,#app{
            height: 100%;
            margin: 0;
            padding: 0;
            width: 100%;
        }
        body{
            overflow-x: hidden;
            overflow-y: auto;
            background: #e7e7e7;
        }
        #app{
            overflow: auto;
        }
        #app #loading-indicators {
            display: flex;
            min-height: 100vh;
            justify-content: center;
            align-items: center;
        }
        @media only screen and (max-width:850px) {
            #app #loading-indicators {
               flex-direction: column;
            }
        }
        #app #loading-indicators .loading-indicator{
            border-radius: 15px;
            box-shadow: rgba(0, 0, 0, 0.12) 0 1px 6px,rgba(0, 0, 0, 0.12) 0 1px 4px;
            height: 200px;
            margin: 20px auto;
            overflow: hidden;
            position: relative;
            width: 322px;
        }
        #app #loading-indicators .loading-indicator h1{
            position: absolute;
            top: 50%;
            left: 50%;
            font-family: sans-serif;
            font-size: 20px;
            transform: translate(-50%,-50%);
            text-align: center;
            margin: 0;
            z-index: 3;
        }
        #app #loading-indicators .loading-indicator::before,
        #app #loading-indicators .loading-indicator::after{
            content: "";
            top: 50%;
            left: 50%;
            position: absolute;
            transform: translate(-50%,-50%);
        }
        #app #loading-indicators .loading-indicator::after{
            background-color: #e9e9e9;
            border-radius: 13px;
            height: calc(100% - 4px);
            width: calc(100% - 4px);
        }
        #app #loading-indicators .loading-indicator::before{
            animation:  loading-indicator-rotation 3s linear infinite;
            background: #03a9f4;
            height: 150px;
            width: 200%;
        }
        #app #loading-indicators #loading-indicator_1::before{
            background: #03a9f4;
        }
        #app #loading-indicators #loading-indicator_2::before{
            background: conic-gradient(red,yellow,lime,aqua,blue,magenta,red);
            height: 200%;
        }
        #app #loading-indicators #loading-indicator_3::before{
            background: conic-gradient(to right,#ff6f00 50%,#03a9f4 50%);
            height: 75px;
        }
        @keyframes loading-indicator-rotation{
            from{
                transform: translateX(-50%) translateY(-50%) rotate(0deg);
            }
            to{
                transform: translateX(-50%) translateY(-50%) rotate(360deg);
            }
        }
    </style>
</head>
<body>
    <div id="app">
        <div id="loading-indicators">
            <div class="loading-indicator" id="loading-indicator_1">
                <h1>Border 1</h1>
            </div>
            <div class="loading-indicator" id="loading-indicator_2">
                <h1>Border 2</h1>
            </div>
            <div class="loading-indicator" id="loading-indicator_3">
                <h1>Border 3</h1>
            </div>
        </div>
    </div>
</body>
</html>